Heretofore, a technique for bending a glass sheet heated at a temperature at which bending is possible is bent into a desired curvature, is known (refer to e.g. JP-A-2005-179124). In this technique, a heated glass sheet is conveyed by a roller conveyer constituted by a plurality of conveying rollers forming a conveying surface, and the conveying rollers are each moved up and down according to the conveyance of the glass sheet, to thereby form a curved surface for bending the glass sheet along the conveying direction on the conveying surface. In this case, the glass sheet is bent in the conveying direction by its own weight so as to fit to the curved surface formed on the conveying surface while the glass sheet is conveyed on the roller conveyer. Accordingly, it is possible to bend the glass sheet into a desired curvature along the conveying direction by up-down movements of the conveying rollers.
Further, in the above technique, after the glass sheet is bent along the conveying direction by the above technique, the glass sheet is conveyed by curving rollers each having an axis curved along a perpendicular direction perpendicular to the conveying direction, during which a heated compressed air is blown from air blowing means to the glass sheet. In this case, the glass sheet is pressed against the curving rollers by the heated compressed air while the glass sheet is conveyed by the curving rollers, whereby the glass sheet is bent along the perpendicular direction perpendicular to the conveying direction. Accordingly, by the wind pressure of air blowing, the glass sheet can be bent into a desired curvature along the perpendicular direction perpendicular to the conveying direction.